Terms used in moving average calculations are:

Subgroup Size |
A set of one or more observations that are used to calculate a value on an SPC chart. Any subgroup size between 1 and 10 can be selected on the Chart tab in the SPC Control Properties dialog box. |

Length of MA |
Length of the moving averages. The value that is specified will be the number of subgroup means that will be included in each average. Any Length between 1 and 24 can be selected on the Chart tab in the SPC Control Properties dialog box. |

Weighting Factor |
Weight to be used in the exponentially weighted moving average. The value specified must be a number between 0 and 1. |

Moving average charts overview.